VIRT: Improving Representation-based Models for Text Matching through Virtual Interaction

With the booming of pre-trained transformers, remarkable progress has been made on textual pair modeling to support relevant natural language applications. Two lines of approaches are developed for text matching: interaction-based models performing full interactions over the textual pair, and representation-based models encoding the pair independently with siamese encoders. The former achieves compelling performance due to its deep interaction modeling ability, yet with a sacrifice in inference latency. The latter is efficient and widely adopted for practical use, however, suffers from severe performance degradation due to the lack of interactions. Though some prior works attempt to integrate interactive knowledge into representation-based models, considering the computational cost, they only perform late interaction or knowledge transferring at the top layers. Interactive information in the lower layers is still missing, which limits the performance of representation-based solutions. To remedy this, we propose a novel \textit{Virtual} InteRacTion mechanism, termed as VIRT, to enable full and deep interaction modeling in representation-based models without \textit{actual} inference computations. Concretely, VIRT asks representation-based encoders to conduct virtual interactions to mimic the behaviors as interaction-based models do. In addition, the knowledge distilled from interaction-based encoders is taken as supervised signals to promise the effectiveness of virtual interactions. Since virtual interactions only happen at the training stage, VIRT would not increase the inference cost. Furthermore, we design a VIRT-adapted late interaction strategy to fully utilize the learned virtual interactive knowledge

A Bidirectional Multi-paragraph Reading Model for Zero-shot Entity Linking

Recently, a zero-shot entity linking task is introduced to challenge the generalization ability of entity linking models. In this task, mentions must be linked to unseen entities and only the textual information is available. In order to make full use of the documents, previous work has proposed a BERT-based model which can only take fixed length of text as input. However, the key information for entity linking may exist in nearly everywhere of the documents thus the proposed model cannot capture them all. To leverage more textual information and enhance text understanding capability, we propose a bidirectional multi-paragraph reading model for the zero-shot entity linking task. Firstly, the model treats the mention context as a query and matches it with multiple paragraphs of the entity description documents. Then, the mention-aware entity representation obtained from the first step is used as a query to match multiple paragraphs in the document containing the mention through an entity-mention attention mechanism. In particular, a new pre-training strategy is employed to strengthen the representative ability. Experimental results show that our bidirectional model can capture long-range context dependencies and outperform the baseline model by 3-4% in terms of accuracy

Infectious shock after liposuction

Abstract Background Liposuction has become one of the most popular cosmetic surgeries in China. However, few studies have discussed infectious shock caused by C. perfringens as one of the causes of death after liposuction. Case presentation A 24-year-old woman was brought to the emergency department (ED) of Guangzhou Chinese Overseas Hospital for treatment. The patient had undergone liposuction in her bilateral lower limbs two days prior. At the ED, the patient was unconscious, and had bilateral equal-sized (diameter, 6 mm) round pupils, no light reflex, a blood pressure (BP) of 71/33 mmHg, a heart rate of 133 bpm, and an SpO2 of 70%. She had bilateral limb swelling, extensive ecchymoses in her lower abdomen and bilateral thighs, local crepitus, blisters, weak pulses on her femoral artery and dorsalis pedis, high skin tension, and hemoglobin of 32 g/L. The patient was diagnosed with Clostridium perfringens infection, and she underwent debridement surgery and supportive treatment. But the patient’s BP could not improve. At 8:28 pm on the day of admission, the patient was declared clinically dead after the electrocardiograph showed a horizontal line and spontaneous respiration ceased. Conclusions Failure to meet surgical disinfection and environmental standards may be the cause of infection of C. perfringens through wounds. Therefore, it is necessary to strengthen the environmental disinfection of the operating room, and standardize the sterile conditions of the operation staff and patients before and during operation. Liposuction surgery necrotizing fasciitis is a rare but fatal complications, especially if diagnosis delay, therefore it is critical for early diagnosis and treatment of gas gangrene

Numerical Investigation on Unsteady Shock Wave/Vortex/Turbulent Boundary Layer Interactions of a Hypersonic Vehicle during Its Shroud Separation

Hypersonic vehicles are drawing more and more attention now and for the near future, especially in the low-altitudes near space, from 20 km to 45 km. The reliable separation of the protecting shroud from the hypersonic vehicle is a prerequisite and critical issue for the success of the entire flight mission. The unsteady multi-body separation characteristics and flow characteristics of hypersonic shroud separation at Mach 7.0 are investigated based on numerical simulation in this paper. The improved delayed detached eddy simulation (IDDES) method, dynamic hybrid overset mesh method, and HLLE++ numerical scheme are used to ensure numerical accuracy. Numerical results show that there are four types of vortexes and three types of shock waves inside the shrouds during the separation process, which generate complex shock wave/vortex/boundary layer interactions. Further, an unsteady process of the expansion-transfer-dissipation of an A-type vortex is found, which is the result of strong shock/vortex/boundary layer interactions. The adverse pressure gradient is the root cause driving the generation and transfer of the A-type vortex during the shroud separation. Furthermore, the transfer process of the A-type vortex only lasts for 5.52 ms but causes a large disturbance to the aerodynamic force of the shroud. The results of this paper could provide a reference for the design of near-space hypersonic vehicles

Synthesis and Fluorescence Properties of 5,7-Diphenylquinoline and 2,5,7-Triphenylquinoline Derived from m-Terphenylamine

Synthesis of 5,7-phenylquinoline from the Skraup reaction of m-terphenyl-amine and glycerol in the presence of acid is reported. Further reaction of 5,7-diphenyl-quinoline with phenyl lithium prepared in situ led to the formation of 2,5,7-triphenyl-quinoline. All of the products and their intermediates were characterized and the UV-Vis and photo-luminescence (PL) spectra of m-terphenylamine, 5,7-diphenylquinoline and 2,5,7-triphenylquinoline are also reported